Emerging treatment paradigms like targeting the tumor microenvironment and/or dosing as part of a metronomic regimen are anticipated to produce better outcomes in ovarian cancer, but current drug delivery systems are lacking. We have designed and evaluated paclitaxel (PTX) and rapamycin (RAP) micellar systems that can be tailored for various dosing regimens and target tumor microenvironment. Individual and mixed PTX/RAP (MIX-M) micelles are prepared by conjugating drugs to a poly(ethylene glycol)-block-poly(β-benzyl l-aspartate) using a pH-sensitive linker. The micelles release the drug(s) at pH 5.5 indicating preferential release in the acidic endosomal/lysosomal environment. Micelles exhibit antiproliferative effects in ovarian cell cancer lines (SKOV-3 (human caucasian ovarian adenocarcinoma) and ES2 (human ovarian clear cell carcinoma)) and an endothelial cell line (HUVEC; human umbilical vein endothelial cells) with the MIX-M being synergistic. The micelles also inhibited endothelial migration and tube formation. In healthy mice, micelles at 60 mg/kg/drug demonstrated no acute toxicity over 21 days. ES2 xenograft model efficacy studies at 20 mg/kg/drug dosed every 4 days and evaluated at 21 days indicate that the individual micelles exhibit antiangiogenic effects, while the MIX-M exhibited both antiangiogenic and apoptotic induction that results in significant tumor volume reduction. On the basis of our results, MIX-M micelles can be utilized to achieve synergistic apoptotic and antiangiogenic effects when treated at frequent low doses.
新兴的治疗方案,如针对肿瘤微环境和/或作为节律给药的一部分的剂量,预计能在卵巢癌中产生更好的治疗效果,但目前的药物输送系统尚显不足。我们设计并评估了可根据不同给药方案定制的
紫杉醇(
PTX)和
雷帕霉素(RAP)胶束系统,旨在靶向肿瘤微环境。通过将药物与聚(
乙烯醇)-区块-聚(β-苄基
L-天冬氨酸)结合,使用pH敏感连接子制备了单一和混合的
PTX/RAP(MIX-M)胶束。胶束在pH 5.5时释放药物,表明其在酸性内体/溶酶体环境中优先释放。胶束在卵巢癌
细胞系(SKOV-3(人类白种卵巢腺癌)和ES2(人类卵巢透明细胞癌))及内皮
细胞系(HU
VEC;人类脐静脉内皮细胞)中表现出抗增殖效果,其中MIX-M表现出协同作用。胶束还抑制了内皮细胞的迁移和管道形成。在健康小鼠中,60 mg/kg/药物的胶束在21天内没有表现出急性毒性。在ES2异种移植模型中,以20 mg/kg/药物每4天给药并在21天进行评估的效果研究表明,单一胶束表现出抗血管生成效应,而MIX-M则展现出抗血管生成和诱导凋亡的双重作用,从而导致显著的肿瘤体积缩减。根据我们的结果,MIX-M胶束可以用于在频繁低剂量的治疗下实现协同的凋亡和抗血管生成效果。